Iron-dependent enzymes in Parkinson's disease.

There is increasing evidence for a mitochondrial disturbance in Parkinson's disease (PD). We present data which favor a defect of complex I of the respiratory chain only in substantia nigra pars compacta. Evidence from literature supports the view that this complex I defect is specific for Parkinson's disease. Questions like feasibility of postmortem biochemical analyses, impairment of the mitochondrial genome, and evidence for the complex I defect as a causative event for PD are discussed in detail. We consider complex I defect to play a most important role in the cell death of dopaminergic neurons.